This post is a follow-up on my Swing Plane series. If you have not read them, I encourage you to give them a look before going through this post. The Swing Plane series can be found on my Resources page here.When it come downs to it, hitting mechanics are really all about the barrel. We can talk until we are blue in the face about coiling this to stretch that but the focus has to be the barrel. How does this movement help us control and/or add speed to the barrel? If we don't know, why are we doing it? In this post, we are going to focus on the barrel, in particular one important aspect of the swing I call releasing the barrel.In the previous Swing Plane articles, we saw that hitters set up there swing plane to release the barrel early or later depending on how they setup their swings (specifically how they use the rear shoulder complex early in the swing). In this post we will examine how they release the barrel.Take a look at Carlos Correa in the still below. In the first frame Correa hasn't started moving the barrel toward the ball. Notice the angle of the bat to the bottom forearm is roughly 90 degrees (pi over two for the math nerds among us). Then at contact, the angle is probably closer to 180 degrees.

At some point in his swing, the angle between the bat and forearm changed. Correa released the barrel. A quick word on terminology. I use release the barrel. I heard the term in the golf world and like it. I've also heard releasing the angle, the hinge angle, releasing the hinge, pivot the bat, many others. I like releasing the barrel because, you know, hitting is all about the barrel.Let's look at some of the variables that can influence barrel release.1. Body rotation. A object rotating around a center of rotation will develop inertia tangential to the radius of movement, like the picture below.

For hitting, the object isn't a fixed ball, it is bat. The bat is held by the hands/wrists, which act sorta like a hinge. So the faster we turn, the more the barrel is going to want to fly off the radius and release (assuming we let it by not locking the wrists). But, as I showed in this video, some hitters use more extension than rotation, which leads us to...2. Extension. No, I don't mean follow-through extension, I am grouping other things in with hip extension. Extension essentially changes the shape of the circle above to more of an oval.3a. Lead shoulder. Hitters can add more torque to the handle by using the pulling nature of the lead shoulder complex. I went into detail about how the lead shoulder works in this article. Think of it sorta like a backhanded frisbee throw.3b. Bottom forearm/wrist. Pretty easy to see that hitters can change the angle of the bat to the forearm by simply adducting the wrist. Adduction takes the thumb away from the body and looks like this. (This movement is also called ulna deviation.) This is a pretty weak movement however.

4a. Rear shoulder. OK. So the rear shoulder complex is a little tricky. I went through its function in this article. If you look at how the rear shoulder works (a page of its articulations can be seen here and associated scapula movements here) we can see the prime movements of the shoulder complex and girdle are really pulling movements. The shoulder movements that take the bat directly to the ball are internal rotation and transverse adduction, pretty crappy movements (IR especially). These movements make up the push swing that we should know by now we don't want. We don't want to use the rear shoulder's direct movements, we want to use the stronger movements to help setup and allow the bigger movements in the swing to happen, mainly torso rotation. Plus we saw in these posts (here and here) that hitters are successful with varying degrees of rear shoulder complex function. In short, the rear shoulder complex and girdle have so many possible movements, we at minimum want to use it in a way to prevent the bad ones. Make sense?4a. Top forearm/wrist. Basically the matching component of the bottom wrist adduction. Early in the swing this will be seen in the form of supination, shown below. Later in the swing both wrists will adduct (post-contact).

If you have a bat handy and a couple minutes to spare get up and fool around with these movements. See how turning the body faster does indeed provide more inertia to the bat. Experiment with the lead shoulder and scap to see how we can apply torque to the handle, causing the bottom hand to want to unhinge. Especially spend some time with top forearm supination. This may seem like a wimpy movement, but at a certain point the biceps kick in to help turn the forearm over. The biceps originate at the scapula, which means forearm supination actually has a (weak) connection to shoulder function. Supination is a relatively strong movement (compared to say pronation) and we will see it is very important to hitting. (Anecdotally, if you have ever met a couple pro ball players, you know from their handshakes that forearms are important to hitting.) OK. Armed with our assortment of variables, let’s see how some pros release the barrel. From last time, we saw that hitters release the barrel earlier for outside pitches, later for inside offerings. We also saw hitters hang onto the release angle for slower pitches, but had to get the barrel released sooner on fastballs to make contact. Thus, we can hypothesize that we would see the biggest difference in releasing the barrel on a high-inside off-speed vs. a low-outside fastball. Maybe we can find such clips. Let’s take a look at Adrian Gonzalez against an 80 mph offering on the inner and upper thirds. Watch the clip a few times at full speed to get a feel for Gonzalez’s intent here.

OK. Now let’s watch the first portion of the swing here.

Notice Gonzalez doesn’t do anything to release the barrel yet. See how he keeps the lead elbow bent (hell, it may even gain flexion) so that the lead shoulder’s turn doesn’t torque the handle and help the bottom wrist unhinge. Any top forearm supination getting the barrel going toward the umpire? Nope. As we can see in the final frame the forearm angle with the bat is still roughly 90 degrees.

You might say that Gonzalez’s focus up to this point is getting the handle to where it needs to be. He can’t release the barrel deeper in the swing because his body is in the way and he would swing right over the pitch early. He has to get the handle out past his body before he can release the barrel. Let’s watch the rest of the swing.

There’s the barrel release. See how the lead scap retracts and pops the flexion out of the lead elbow. See how the top forearm turns under instead of just chopping down on the ball. The barrel works under the ball to give the ball some lift upon contact. He’s not just chopping wood with simple elbow extension.

Let’s look at the opposite extreme, a low-outside fastball. I got this clip this year in Spring Training. It was the first weekend of games and it doesn’t look like Gonzalez had his timing yet, this fastball completely ate his lunch. But it gives a look at his swing process. Here’s the clip.

Pretty stark difference from what we saw with the slower inside pitch. Gonzalez’s thought process is all about the barrel. No time for the stupid handle. Gonzalez nearly hits it out of the catcher’s glove! See how he immediately gets the lead shoulder around to take the flexion out of the lead elbow to help unhinge the bottom wrist. See how RIGHT NOW he starts turning over the barrel with the top forearm. Let’s watch the initial part of the swing again. See how the barrel starts working toward the umpire now, like right now.

Let’s be honest here, what’s swinging the bat? It ain’t the legs, it ain’t the torso. Gonzalez is pretty much swinging with just the lead shoulder and the top forearm. The result wasn’t great, a single to the 5.5 hole, but we can use the two extreme examples to draw a line through. We can see that Gonzalez employs lead scap retraction/ shoulder turn and top hand supination to release the barrel. He varies the timing of each movement based on pitch speed and location.Last time we saw how Bryce Harper handled inside and outside pitches – varying the time of barrel release. However, if you go back and look, we kinda took it easy on him with the outside pitch at belt level. Let’s crank up the intensity with a lower pitch on the outer third.

What do we see? The lead arm quickly losing the flexion and super early top forearm turning. Can you see the intent? Is Harper OK with just chopping down on the ball or is he driven to get the barrel underneath the ball? Watch it Posey, stick that glove out any further you are going to lose it. How about Kris Bryant. Let’s see if he has the goods to handle the high inside pitch. What’s the focus at the initial part of the swing?

Getting the handle where it needs to be. How about on this outside fastball?

The barrel baby. Bryant could work for Jack Daniel’s, because he’s delivering barrels. As I mentioned on my Twitter feed, slow motion doesn’t do this last clip justice. Watch it in full speed to see what is going on.

Buster Posey – professional hitter. See how on the outside pitch (left) he gets the lead shoulder working early to help unhinge the bottom wrist. One is a little different look because the outside pitch is high and the inside pitch is low. See how Posey gets the barrel flatter to hit the outside pitch.

One more, the King of Supination Mike Trout. Inside pitch.

Outside pitch. It’s pretty obvious what he is doing. Can you see how the bat is getting yanked by his top forearm turning under? See how on this pitch he nearly takes it out of the glove like we saw Gonzalez do. But we don’t see that on the inside pitch above.

The astute reader may notice that the variables used for releasing the barrel may become maxed out and pose problems. For instance, for high-inside fastballs we simply may run out of space and time to get the handle through to release the barrel. And for low outside pitches releasing the barrel early makes it hard to control the bat much less keep the barrel speed up. You might guess that the two extremes would be the hardest pitches to hit, and you would be correct. The graph below (taken from this awesome article) shows wOBA based on pitch location. We can clearly see that high-tight and low-away are the least productive pitch locations from an offensive standpoint. We can also see why more pitches are thrown in the bottom-outside quadrant than any other.

We can see that low-outside is a little more difficult. Pretty much no getting away from the law of conservation of momentum. She is a cruel mistress. Still, high and tight is no day at the beach either. Take a look at this clip of Gonzalez handling a 92 mph FB high and tight.

That’s really pretty impressive. Look how tight Gonzalez keeps the barrel to his body (holding the release angle, conserving angular momentum) to get the handle through. Notice how late he snaps the lead scap back to release the barrel. Looks like he is squishing something in his armpit. Phew. Man that’s good. Some hitters vary their posture to give them a little more room as well. Here’s Donaldson showing that very thing. Notice less side bend on the high and tight pitch on the right.

We saw the same thing last time with Andrew McCutchen. These guys (along with Todd Frazier, Robinson Cano, and Harper) get a little more aggressive with the lead shoulder turn (and/or protraction) during the stride. Thus, we will see some turn/retraction regardless of pitch location or speed just to “get out of the hole.”

They will rely on the rest of the shoulder and scap’s motion with forearm turn to give them margin for adjustment. If that isn’t enough, some posture adjustment is necessary. For guys like Gonzalez (and Pujols, Cabrera) who don’t get a big shoulder turn or protraction early, you will see more variability in how the elbow flexes vs. how the posture changes. Once again, you have to find what works for you. Regardless, the lead shoulder is a variable used for adjustments. Below we see with Pujols' shorter lead arm radius (from less lead scap protraction), he is able to get the barrel through on the inside pitch without adjusting his posture.

The other variable is top forearm turn or supination. In this study, researchers found that grip strength correlates with offensive production with a r value .317. For something has multi-faceted as hitting that value is actually quite telling. I would imagine if they tested supinator strength the correlation may even be higher. They also found average grip strength increased at every level of the minor leagues. The connection the body has with the bat is pretty important. Well, this is a lot to digest. In an upcoming post I will show some practice work hitters can do to strengthen this movements to have better command of releasing the barrel in their swings. If you want a hint at what we are going to be doing, talk a look at Michael Brantley and Josh Reddick. Until next, time pride in your hitting!